This invention relates to the use of mesembrine and related compounds as serotonin-uptake inhibitors, to pharmaceutical compositions comprising as an active ingredient dry material or an extract of a plant of the family Mesembryanthemaceae, standardised as to its active content, and to new compounds.
It is known that the naturally occurring alkaloid mesembrine is useful as a medicament having CNS-stimulating action (see JP71043539 to Tanabe Seiyaku Company Limited).
It is also known that a plant and plant products known colloquially as "kougoed", "channa" or "kanna" in the Cape of South Africa, are used traditionally by some communities as inebriants, sedatives and to elevate mood. The plants called "kougoed", "channa" or "kanna" are all members of the family Mesembryanthemaceae, and contains varying amounts of (-)-mesembrine and related alkaloids.
An article entitled Psychoactive constituents of the genus Sceletium N.E.Br. and other Mesembryanthemaceae: a review, by Smith et al, in Journal of Ethnopharmacology, 50 (1996), Pages 119 to 130, reviews the historical data recorded over 300 year period of the use of Sceletium plants in psychoactive preparations, describes techniques for the preparation and use of "kougoed" from plants of Sceletium and documents the subjective experiences of a number of contemporary users. The alkaloid distribution in Sceletium and other members of the family Mesembryanthemaceae are also considered. Chemical studies have indicated as many as nine alkaloids in Sceletium, which fall into three distinct structural categories.